| 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | #ifndef _VHOST_H |
| 3 | #define _VHOST_H |
| 4 | |
| 5 | #include <linux/eventfd.h> |
| 6 | #include <linux/vhost.h> |
| 7 | #include <linux/mm.h> |
| 8 | #include <linux/mutex.h> |
| 9 | #include <linux/poll.h> |
| 10 | #include <linux/file.h> |
| 11 | #include <linux/uio.h> |
| 12 | #include <linux/virtio_config.h> |
| 13 | #include <linux/virtio_ring.h> |
| 14 | #include <linux/atomic.h> |
| 15 | #include <linux/vhost_iotlb.h> |
| 16 | #include <linux/irqbypass.h> |
| 17 | |
| 18 | struct vhost_work; |
| 19 | struct vhost_task; |
| 20 | typedef void (*vhost_work_fn_t)(struct vhost_work *work); |
| 21 | |
| 22 | #define VHOST_WORK_QUEUED 1 |
| 23 | struct vhost_work { |
| 24 | struct llist_node node; |
| 25 | vhost_work_fn_t fn; |
| 26 | unsigned long flags; |
| 27 | }; |
| 28 | |
| 29 | struct vhost_worker { |
| 30 | struct vhost_task *vtsk; |
| 31 | struct llist_head work_list; |
| 32 | u64 kcov_handle; |
| 33 | }; |
| 34 | |
| 35 | /* Poll a file (eventfd or socket) */ |
| 36 | /* Note: there's nothing vhost specific about this structure. */ |
| 37 | struct vhost_poll { |
| 38 | poll_table table; |
| 39 | wait_queue_head_t *wqh; |
| 40 | wait_queue_entry_t wait; |
| 41 | struct vhost_work work; |
| 42 | __poll_t mask; |
| 43 | struct vhost_dev *dev; |
| 44 | }; |
| 45 | |
| 46 | void vhost_work_init(struct vhost_work *work, vhost_work_fn_t fn); |
| 47 | void vhost_work_queue(struct vhost_dev *dev, struct vhost_work *work); |
| 48 | bool vhost_has_work(struct vhost_dev *dev); |
| 49 | |
| 50 | void vhost_poll_init(struct vhost_poll *poll, vhost_work_fn_t fn, |
| 51 | __poll_t mask, struct vhost_dev *dev); |
| 52 | int vhost_poll_start(struct vhost_poll *poll, struct file *file); |
| 53 | void vhost_poll_stop(struct vhost_poll *poll); |
| 54 | void vhost_poll_queue(struct vhost_poll *poll); |
| 55 | void vhost_dev_flush(struct vhost_dev *dev); |
| 56 | |
| 57 | struct vhost_log { |
| 58 | u64 addr; |
| 59 | u64 len; |
| 60 | }; |
| 61 | |
| 62 | enum vhost_uaddr_type { |
| 63 | VHOST_ADDR_DESC = 0, |
| 64 | VHOST_ADDR_AVAIL = 1, |
| 65 | VHOST_ADDR_USED = 2, |
| 66 | VHOST_NUM_ADDRS = 3, |
| 67 | }; |
| 68 | |
| 69 | struct vhost_vring_call { |
| 70 | struct eventfd_ctx *ctx; |
| 71 | struct irq_bypass_producer producer; |
| 72 | }; |
| 73 | |
| 74 | /* The virtqueue structure describes a queue attached to a device. */ |
| 75 | struct vhost_virtqueue { |
| 76 | struct vhost_dev *dev; |
| 77 | |
| 78 | /* The actual ring of buffers. */ |
| 79 | struct mutex mutex; |
| 80 | unsigned int num; |
| 81 | vring_desc_t __user *desc; |
| 82 | vring_avail_t __user *avail; |
| 83 | vring_used_t __user *used; |
| 84 | const struct vhost_iotlb_map *meta_iotlb[VHOST_NUM_ADDRS]; |
| 85 | struct file *kick; |
| 86 | struct vhost_vring_call call_ctx; |
| 87 | struct eventfd_ctx *error_ctx; |
| 88 | struct eventfd_ctx *log_ctx; |
| 89 | |
| 90 | struct vhost_poll poll; |
| 91 | |
| 92 | /* The routine to call when the Guest pings us, or timeout. */ |
| 93 | vhost_work_fn_t handle_kick; |
| 94 | |
| 95 | /* Last available index we saw. */ |
| 96 | u16 last_avail_idx; |
| 97 | |
| 98 | /* Caches available index value from user. */ |
| 99 | u16 avail_idx; |
| 100 | |
| 101 | /* Last index we used. */ |
| 102 | u16 last_used_idx; |
| 103 | |
| 104 | /* Used flags */ |
| 105 | u16 used_flags; |
| 106 | |
| 107 | /* Last used index value we have signalled on */ |
| 108 | u16 signalled_used; |
| 109 | |
| 110 | /* Last used index value we have signalled on */ |
| 111 | bool signalled_used_valid; |
| 112 | |
| 113 | /* Log writes to used structure. */ |
| 114 | bool log_used; |
| 115 | u64 log_addr; |
| 116 | |
| 117 | struct iovec iov[UIO_MAXIOV]; |
| 118 | struct iovec iotlb_iov[64]; |
| 119 | struct iovec *indirect; |
| 120 | struct vring_used_elem *heads; |
| 121 | /* Protected by virtqueue mutex. */ |
| 122 | struct vhost_iotlb *umem; |
| 123 | struct vhost_iotlb *iotlb; |
| 124 | void *private_data; |
| 125 | u64 acked_features; |
| 126 | u64 acked_backend_features; |
| 127 | /* Log write descriptors */ |
| 128 | void __user *log_base; |
| 129 | struct vhost_log *log; |
| 130 | struct iovec log_iov[64]; |
| 131 | |
| 132 | /* Ring endianness. Defaults to legacy native endianness. |
| 133 | * Set to true when starting a modern virtio device. */ |
| 134 | bool is_le; |
| 135 | #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY |
| 136 | /* Ring endianness requested by userspace for cross-endian support. */ |
| 137 | bool user_be; |
| 138 | #endif |
| 139 | u32 busyloop_timeout; |
| 140 | }; |
| 141 | |
| 142 | struct vhost_msg_node { |
| 143 | union { |
| 144 | struct vhost_msg msg; |
| 145 | struct vhost_msg_v2 msg_v2; |
| 146 | }; |
| 147 | struct vhost_virtqueue *vq; |
| 148 | struct list_head node; |
| 149 | }; |
| 150 | |
| 151 | struct vhost_dev { |
| 152 | struct mm_struct *mm; |
| 153 | struct mutex mutex; |
| 154 | struct vhost_virtqueue **vqs; |
| 155 | int nvqs; |
| 156 | struct eventfd_ctx *log_ctx; |
| 157 | struct vhost_worker *worker; |
| 158 | struct vhost_iotlb *umem; |
| 159 | struct vhost_iotlb *iotlb; |
| 160 | spinlock_t iotlb_lock; |
| 161 | struct list_head read_list; |
| 162 | struct list_head pending_list; |
| 163 | wait_queue_head_t wait; |
| 164 | int iov_limit; |
| 165 | int weight; |
| 166 | int byte_weight; |
| 167 | bool use_worker; |
| 168 | int (*msg_handler)(struct vhost_dev *dev, u32 asid, |
| 169 | struct vhost_iotlb_msg *msg); |
| 170 | }; |
| 171 | |
| 172 | bool vhost_exceeds_weight(struct vhost_virtqueue *vq, int pkts, int total_len); |
| 173 | void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, |
| 174 | int nvqs, int iov_limit, int weight, int byte_weight, |
| 175 | bool use_worker, |
| 176 | int (*msg_handler)(struct vhost_dev *dev, u32 asid, |
| 177 | struct vhost_iotlb_msg *msg)); |
| 178 | long vhost_dev_set_owner(struct vhost_dev *dev); |
| 179 | bool vhost_dev_has_owner(struct vhost_dev *dev); |
| 180 | long vhost_dev_check_owner(struct vhost_dev *); |
| 181 | struct vhost_iotlb *vhost_dev_reset_owner_prepare(void); |
| 182 | void vhost_dev_reset_owner(struct vhost_dev *dev, struct vhost_iotlb *iotlb); |
| 183 | void vhost_dev_cleanup(struct vhost_dev *); |
| 184 | void vhost_dev_stop(struct vhost_dev *); |
| 185 | long vhost_dev_ioctl(struct vhost_dev *, unsigned int ioctl, void __user *argp); |
| 186 | long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *argp); |
| 187 | bool vhost_vq_access_ok(struct vhost_virtqueue *vq); |
| 188 | bool vhost_log_access_ok(struct vhost_dev *); |
| 189 | void vhost_clear_msg(struct vhost_dev *dev); |
| 190 | |
| 191 | int vhost_get_vq_desc(struct vhost_virtqueue *, |
| 192 | struct iovec iov[], unsigned int iov_count, |
| 193 | unsigned int *out_num, unsigned int *in_num, |
| 194 | struct vhost_log *log, unsigned int *log_num); |
| 195 | void vhost_discard_vq_desc(struct vhost_virtqueue *, int n); |
| 196 | |
| 197 | bool vhost_vq_is_setup(struct vhost_virtqueue *vq); |
| 198 | int vhost_vq_init_access(struct vhost_virtqueue *); |
| 199 | int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len); |
| 200 | int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads, |
| 201 | unsigned count); |
| 202 | void vhost_add_used_and_signal(struct vhost_dev *, struct vhost_virtqueue *, |
| 203 | unsigned int id, int len); |
| 204 | void vhost_add_used_and_signal_n(struct vhost_dev *, struct vhost_virtqueue *, |
| 205 | struct vring_used_elem *heads, unsigned count); |
| 206 | void vhost_signal(struct vhost_dev *, struct vhost_virtqueue *); |
| 207 | void vhost_disable_notify(struct vhost_dev *, struct vhost_virtqueue *); |
| 208 | bool vhost_vq_avail_empty(struct vhost_dev *, struct vhost_virtqueue *); |
| 209 | bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *); |
| 210 | |
| 211 | int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, |
| 212 | unsigned int log_num, u64 len, |
| 213 | struct iovec *iov, int count); |
| 214 | int vq_meta_prefetch(struct vhost_virtqueue *vq); |
| 215 | |
| 216 | struct vhost_msg_node *vhost_new_msg(struct vhost_virtqueue *vq, int type); |
| 217 | void vhost_enqueue_msg(struct vhost_dev *dev, |
| 218 | struct list_head *head, |
| 219 | struct vhost_msg_node *node); |
| 220 | struct vhost_msg_node *vhost_dequeue_msg(struct vhost_dev *dev, |
| 221 | struct list_head *head); |
| 222 | void vhost_set_backend_features(struct vhost_dev *dev, u64 features); |
| 223 | |
| 224 | __poll_t vhost_chr_poll(struct file *file, struct vhost_dev *dev, |
| 225 | poll_table *wait); |
| 226 | ssize_t vhost_chr_read_iter(struct vhost_dev *dev, struct iov_iter *to, |
| 227 | int noblock); |
| 228 | ssize_t vhost_chr_write_iter(struct vhost_dev *dev, |
| 229 | struct iov_iter *from); |
| 230 | int vhost_init_device_iotlb(struct vhost_dev *d); |
| 231 | |
| 232 | void vhost_iotlb_map_free(struct vhost_iotlb *iotlb, |
| 233 | struct vhost_iotlb_map *map); |
| 234 | |
| 235 | #define vq_err(vq, fmt, ...) do { \ |
| 236 | pr_debug(pr_fmt(fmt), ##__VA_ARGS__); \ |
| 237 | if ((vq)->error_ctx) \ |
| 238 | eventfd_signal((vq)->error_ctx, 1);\ |
| 239 | } while (0) |
| 240 | |
| 241 | enum { |
| 242 | VHOST_FEATURES = (1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | |
| 243 | (1ULL << VIRTIO_RING_F_INDIRECT_DESC) | |
| 244 | (1ULL << VIRTIO_RING_F_EVENT_IDX) | |
| 245 | (1ULL << VHOST_F_LOG_ALL) | |
| 246 | (1ULL << VIRTIO_F_ANY_LAYOUT) | |
| 247 | (1ULL << VIRTIO_F_VERSION_1) |
| 248 | }; |
| 249 | |
| 250 | /** |
| 251 | * vhost_vq_set_backend - Set backend. |
| 252 | * |
| 253 | * @vq Virtqueue. |
| 254 | * @private_data The private data. |
| 255 | * |
| 256 | * Context: Need to call with vq->mutex acquired. |
| 257 | */ |
| 258 | static inline void vhost_vq_set_backend(struct vhost_virtqueue *vq, |
| 259 | void *private_data) |
| 260 | { |
| 261 | vq->private_data = private_data; |
| 262 | } |
| 263 | |
| 264 | /** |
| 265 | * vhost_vq_get_backend - Get backend. |
| 266 | * |
| 267 | * @vq Virtqueue. |
| 268 | * |
| 269 | * Context: Need to call with vq->mutex acquired. |
| 270 | * Return: Private data previously set with vhost_vq_set_backend. |
| 271 | */ |
| 272 | static inline void *vhost_vq_get_backend(struct vhost_virtqueue *vq) |
| 273 | { |
| 274 | return vq->private_data; |
| 275 | } |
| 276 | |
| 277 | static inline bool vhost_has_feature(struct vhost_virtqueue *vq, int bit) |
| 278 | { |
| 279 | return vq->acked_features & (1ULL << bit); |
| 280 | } |
| 281 | |
| 282 | static inline bool vhost_backend_has_feature(struct vhost_virtqueue *vq, int bit) |
| 283 | { |
| 284 | return vq->acked_backend_features & (1ULL << bit); |
| 285 | } |
| 286 | |
| 287 | #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY |
| 288 | static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq) |
| 289 | { |
| 290 | return vq->is_le; |
| 291 | } |
| 292 | #else |
| 293 | static inline bool vhost_is_little_endian(struct vhost_virtqueue *vq) |
| 294 | { |
| 295 | return virtio_legacy_is_little_endian() || vq->is_le; |
| 296 | } |
| 297 | #endif |
| 298 | |
| 299 | /* Memory accessors */ |
| 300 | static inline u16 vhost16_to_cpu(struct vhost_virtqueue *vq, __virtio16 val) |
| 301 | { |
| 302 | return __virtio16_to_cpu(vhost_is_little_endian(vq), val); |
| 303 | } |
| 304 | |
| 305 | static inline __virtio16 cpu_to_vhost16(struct vhost_virtqueue *vq, u16 val) |
| 306 | { |
| 307 | return __cpu_to_virtio16(vhost_is_little_endian(vq), val); |
| 308 | } |
| 309 | |
| 310 | static inline u32 vhost32_to_cpu(struct vhost_virtqueue *vq, __virtio32 val) |
| 311 | { |
| 312 | return __virtio32_to_cpu(vhost_is_little_endian(vq), val); |
| 313 | } |
| 314 | |
| 315 | static inline __virtio32 cpu_to_vhost32(struct vhost_virtqueue *vq, u32 val) |
| 316 | { |
| 317 | return __cpu_to_virtio32(vhost_is_little_endian(vq), val); |
| 318 | } |
| 319 | |
| 320 | static inline u64 vhost64_to_cpu(struct vhost_virtqueue *vq, __virtio64 val) |
| 321 | { |
| 322 | return __virtio64_to_cpu(vhost_is_little_endian(vq), val); |
| 323 | } |
| 324 | |
| 325 | static inline __virtio64 cpu_to_vhost64(struct vhost_virtqueue *vq, u64 val) |
| 326 | { |
| 327 | return __cpu_to_virtio64(vhost_is_little_endian(vq), val); |
| 328 | } |
| 329 | #endif |